Injection hose for concrete construction joints

ABSTRACT

An injection hose (1) for concrete construction joints has a substantially liquid-tight base body (2) made of a flexible material such as rubber or plastics that encloses a passage (3). The outer surface (4) of the base body (2) is provided with at least one groove-shaped recess (5) that extends over its whole length. Radial outlets (6) for the liquid injected through the passage (3) are distributed over the length of the recess (5). A strip made of a material that may be compressed under the inner pressure of the injection liquid is received in the recess (5) and covers the outlets (6). A liquid-permeable sheath (8) surrounds the base body (2) and the strip, in the manner of a hose. A single recess (5) extends with a predetermined pitch along a spiral path around the outer surface (4) of the base body (2) or extends parallel to the axis of the passage (3) but has an opening angle of more than 90°.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority from PCT International Application No.PCT/EP94/03174 filed on Sep. 22, 1994. The PCT Application claimspriority from German Application P4332589.0 filed Sep. 24, 1993.

BACKGROUND OF THE INVENTION

An injection tube for construction joints on concrete buildings is knownfrom DE-U 8,425,518, having an essentially cylindrical wall which ispermeable to liquid and is made of flexible material, such as rubber orplastic, in which the wall has a slot, extending over its length, forthe outlet of the injection liquid, the wall in the region of the slothas a depression, extending axially likewise over the length of thewall, for receiving a strip which covers the slot and is made of amaterial which is compressible under the pressure of the injectionliquid, and in which the wall with the strip is enclosed by a tube ofmaterial which is permeable to liquid. Such an injection tube hasdisadvantages in terms of manufacture and, owing to the relativelynarrow outlet slot compared to the width of the depression, relativelyhigh compression forces are required without being able to achieve areliably uniform distribution of the injection liquid over thecircumference of the injection tube.

These disadvantages are avoided to a great extent in the injection tubeknown from DE-A 3,512,470, in that a plurality of radial openings in thebasic body and the assigned depressions and strips are distributed overthe circumference of the basic body with angular symmetry in relation tothe longitudinal mid-axis. However, this requires greater productionexpenditure.

SUMMARY OF THE INVENTION

The object of the invention is to propose an injection tube of the typementioned at the beginning, which, with simple manufacture andrelatively low compression forces, allows a uniform distribution of theinjection liquid over the circumference of the injection tube so thatconstruction joints can be grouped reliably, even using cement.

This object is achieved according to the invention by the characterizingfeatures of claim 1 or claim 3.

With the aid of both solutions, the production of the injection tube issimplified since only a single depression has to be provided in thecasing surface of the basic body, on the other hand the disadvantages ofa continuous slot in the basic body are avoided because radial passageopenings distributed over the length of the basic body are provided, andan exceptionally uniform distribution of the injection liquid over thecircumference of the injection tube is surprisingly achieved either dueto the helical shape of the depression or the relatively large width ofthe depression, so that construction joints can be sealed off withgreater reliability. Particularly if the relatively wide depression runsaxially parallel to the passage channel, to use less material provisionmay be made for the passage channel to be arranged eccentrically in thecylindrical basic body.

It is particularly advantageous if the covering consists of alarge-mesh, low-stretch fabric which tightly surrounds the casingsurface of the basic body and the outer surface of the strip because, inthis way, the injection tube does not undergo any circumferentialwidening at all during compression of the injection liquid, but only aninternal valve effect occurs due to the squeezing of the strip material.This is because the strip, which closes the openings in thegroove-shaped depression when there is an external pressure, for examplethe pressure of the concrete, specifically all the better, the greaterthe external pressure is, is compressed from the inside under thecompression force in such a way that the injection liquid can easilyemerge. In this case, owing to the low-stretch fabric, the injectiontube cannot change its cross-section, which could otherwise lead toincomplete sealing of the construction joint.

In terms of manufacture, it is advantageous if the strip is bonded underprestress into the depression.

Within the scope of the invention, the lateral boundary flanks of thedepression and of the strip can advantageously taper obliquely towardsone another from radially outside to radially inside in a manner knownper se. In this case, a particularly favourable opening cross-sectionresults when there is a compression force from the inside, and aparticularly reliable sealing of the passage channel results when thereis pressure from the outside.

The opening cross-section can also be favourably influenced in the caseof reliable sealing due to the fact that the width of the base area ofthe depression is only slightly larger than the diameter of theopenings.

In a particular design of the invention, the depression and the striphave an essentially mutually corresponding, trapezoidal cross-sectionwith a slightly curved base area and a curved outer surfacecorresponding to the tube circumference so that, in the state of rest,the strip virtually completely fills the depression.

The distance between the radial openings in the depression is in theorder of magnitude of 1 to 3 cm, their diameter between about 3 and 5mm. A diameter of between about 5 and 10 mm is expedient for thecross-section of the passage channel, depending on the groutingmaterial. The depth of the depression is approximately in the order ofmagnitude of between 2 and 5 mm. This then also corresponds to thethickness of the strips in the non-compressed state. A suitable materialfor the basic body is, in particular, polyvinyl chloride, for the stripfoam rubber, sponge rubber or neoprene. The tube-like covering can be alarge-mesh, low-stretch braided fabric.

BRIEF DESCRIPTION OF THE DRAWING

The invention will subsequently be further described with reference toexemplary embodiments and the drawing.

FIG. 1a shows an oblique view of the basic body of an injection tubeexhibiting the invention according to a first embodiment,

FIG. 1b shows a cut-away view of a strip for arrangement in thegroove-like, hectically encircling depression of the basic bodyaccording to FIG. 1a,

FIG. 1c shows the section of a tube-like covering for the basic bodyaccording to FIG. 1a after insertion of the strip according to FIG. 1bin the groove-like, hectically encircling depression,

FIG. 1d shows a cross-section through an injection tube exhibiting theinvention according to the first embodiment after assembly of the partsaccording to FIGS. 1a to 1b,

FIG. 2 shows a cross-section similar to FIG. 1d for another design ofthe invention,

FIG. 3 shows a section corresponding to FIG. 1d for a further design ofthe invention and

FIG. 4 shows a cross-section similar to FIG. 3 and including a passagechannel arranged eccentrically in the body.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The injection tube 1 consists of a basic body 2 which has an essentiallyhollow-cylindrical wall and thus forms a continuous, either central(FIGS 1a, 1d and 3) or eccentric, axially parallel, cylindrical passagechannel 3. An injection liquid, which later hardens, is pressed throughthe passage channel 3 from one end or both ends of the injection tube 1or, if appropriate, in the case of connections provided between saidends also from the latter in order to distribute it over the length of aconstruction joint, to be sealed off, of a concrete building, into whichconstruction joint the injection tube 1 is inserted. According to FIGS1a and 1d, the outer casing surface 4 of the basic body 2 is fitted witha groove-like, hectically encircling depression 5 extending over thelength of the basic body 2. opening out into the depression 5 are radialopenings 6, distributed over the length of the depression, for theoutlet of injection liquid from the passage channel 3 into theconstruction joint to be sealed off. An elongate strip 7 covering theopenings 6 (FIG. 1b) is inserted in the depression 5. The strip 7consists of a material, such as neoprene, which is compressible underthe internal pressure (compression force) of the injection liquid. Inorder to hold the strip 7 in the depression 5 and to avoid widening ofthe cross-section of the injection tube 1, even during compression, thebasic body 2 with the inserted strip 7 is tightly enclosed by atube-like covering 8 which is permeable to liquid. Owing to the factthat the single depression 5 encircles the basic body hectically, theinjection liquid can emerge, during compression, distributed uniformlyvirtually over the entire circumference of the injection tube 1 despiteusing only a single strip 7. The covering 8 preferably consists of alarge-mesh, low-stretch fabric which tightly surrounds the casingsurface 4 of the basic body 2 and the outer surface 9 of the strip 7 andprevents yielding of the strip 7, even under increased internal pressure(compression force). The large-mesh design of the fabric guarantees anunimpeded outlet of the injection liquid during compression over theentire circumference of the injection tube 1 while it conversely allowsa pressure from the outside, for example of the concrete, on the strip7, as a result of which the latter is pressed firmly into the depression5 and sealing of the injection tube 1 from the outside is ensured sothat no disadvantageous materials can pass into the passage channel 3and block it. By means of the solution according to the invention, aninternal valve device is therefore provided which is functional at anytime and guarantees a uniform distribution of the injection liquidduring the grouting of a construction joint to be sealed off, withoutwidening of the cross-section of the injection tube.

If, as can be seen from FIG. 2, the passage channel 3 is arrangedeccentrically in the cylindrical basic body 2, the tube cross-sectioncan have a relatively small cross-section despite a relatively largethickness of the strip 7 and therefore a good opening and closingfunction. In this case, the embodiment according to FIG. 2 relates to aninjection tube 1, in which the depression 5 and the strip 7 run axiallyparallel to the passage channel 3, and the depression 5 has an openingwidth a of less or more than 90°.

The embodiment illustrated in FIG. 3 is likewise an injection tube 1whose depression 5 and strip 7 run axially parallel to the passagechannel 3, but the depression 5 extends over an opening width a of morethan 90° so that, in this way, a sufficiently uniform distribution ofthe injection liquid can be achieved over the circumference of theinjection tube 1 during compression.

It is common to all the special designs illustrated that the lateralboundary flanks 10 of the depression 5 and of the strip 7 run obliquelytowards one another from radially outside to radially inside. Thedepression 5 and the strip 7 then preferably have an essentiallymutually corresponding, trapezoidal cross-section with a slightly curvedbase area 11 of the strip 7 or of the depression 5 and a curved outersurface 9 of the strip 7 corresponding to the tube circumference. It isalso common to all the designs that the width of the base area 11 of thedepression 5 is only slightly larger than the diameter of the radialopenings 6, such that the internal valve device of the injection tube 1according to the invention already opens at relatively low compressionforces, but on the other hand reliable sealing is guaranteed when thestrip 7 is pressurized from the outside. Instead of the trapezoidalcross-section of the depression, the latter can, of course, also haveany desired other shape as long as it is suitable to receive acorresponding, compressible strip, a round cord or the like. Forexample, it can be shaped to be semicircular, oval or the like.

I claim:
 1. An injection tube (1) for construction joints on concrete buildings comprising:a basic body (2) comprising a flexible material which is essentially impermeable to liquid, said basic body surrounding a passage channel (3) and having an outer casing surface (4), at least one groove-like depression (5) extending over the length of the basic body (2), one said depression (5) hectically encircling the outer casing surface (4) of the basic body (2) with a predetermined pitch; a plurality of radial openings (6) fluidly connecting the passage channel (3) to the depression (5) over the length of the depression (5), said openings providing an outlet for a liquid injected into the passage channel (3); said depression (5) receiving a strip (7) comprising a material which is compressible under the internal pressure of the injection liquid, said strip (7) covering the openings (6); and a covering (8) which is permeable to liquid enclosing the basic body (2) and the strip (7).
 2. An injection tube (1) for construction joints on concrete buildings comprising:a basic body (2) comprising a flexible material which is essentially impermeable to liquid, said basic body surrounding a passage channel (3) and having an outer casing surface (4), at least one groove-like depression (5) extending over the length of the basic body (2), one said depression (5) running axially parallel to the passage channel (3) and having an opening width of more than 90°; a plurality of radial openings (6) fluidly connecting the passage channel (3) to the depression (5) over the length of the depression (5), said openings providing an outlet for a liquid injected into the passage channel (3); said depression (5) receiving a strip (7) comprising a material which is compressible under the internal pressure of the injection liquid, said strip (7) covering the openings (6); and a covering (8) which is permeable to liquid enclosing the basic body (2) and the strip (7).
 3. An injection tube according to claim 1, wherein the passage channel (3) is arranged eccentrically in the cylindrical basic body (2).
 4. An injection tube according to claim 1, wherein the covering (8) consists of a large-mesh, low-stretch fabric which tightly surrounds the casing surface (4) of the basic body (2) and an outer surface of the strip (7).
 5. An injection tube according to claim 1, wherein the strip (7) is bonded under prestress into the depression (5).
 6. An injection tube according to claim 1, wherein the depression (5) and the strip (7) have lateral boundary flanks which taper obliquely towards one another from radially outside to radially inside.
 7. An injection tube according to claim 1, wherein the depression (5) has a base area and the width of the base area (11) of the depression (5) is only slightly larger than a diameter of the openings (6).
 8. An injection tube according to claim 1, wherein the depression (5) and the strip (7) have an essentially mutually corresponding, trapezoidal cross-section with a slightly curved base area (11) and a curved outer surface (9) corresponding to the tube circumference.
 9. An infection tube according to claim 2, wherein the covering (8) consists of a large-mesh, low-stretch fabric which tightly surrounds the casing surface (4) of the basic body (2) and an outer surface of the strip (7).
 10. An injection tube according to claim 9, wherein the strip (7) is bonded under prestress into the depression (5).
 11. An injection tube according to claim 10, wherein the depression (5) and the strip (7) have lateral boundary flanks which taper obliquely towards one another from radially outside to radially inside.
 12. An injection tube according to claim 11, wherein the depression (5) has a base area and the width of the base area (11) of the depression (5) is only slightly larger than a diameter of the openings (6).
 13. An injection tube according to claim 12, wherein the depression (5) and the strip (7) have an essentially mutually corresponding, trapezoidal cross-section with a slightly curved base area (11) and a curved outer surface (9) corresponding to the tube circumference.
 14. An injection tube according to claim 2, wherein the passage channel (3) is arranged eccentrically in the cylindrical basic body (2).
 15. An injection tube according to claim 3, wherein the depression (5) and the strip (7) have lateral boundary flanks which taper obliquely towards one another from radially outside to radially inside.
 16. An injection tube according to claim 3, wherein the depression (5) has a base area and the width of the base area (11) of the depression (5) is only slightly larger than a diameter of the openings (6).
 17. An injection tube according to claim 3, wherein the depression (5) and the strip (7) have an essentially mutually corresponding, trapezoidal cross-section with a slightly curved base area (11) and a curved outer surface (9) corresponding to the tube circumference.
 18. An injection tube according to claim 2, wherein the depression (5) and the strip (7) have lateral boundary flanks which taper obliquely towards one another from radially outside to radially inside.
 19. An injection tube according to claim 2, wherein the depression (5) has a base area and the width of the base area (11) of the depression (5) is only slightly larger than the diameter of the openings (6).
 20. An injection tube according to claim 2, wherein the depression (5) and the strip (7) have an essentially mutually corresponding, trapezoidal cross-section with a slightly curved base area (11) and a curved outer surface (9) corresponding to the tube circumference. 